This $5 meal is giving KFC a huge advantage over Chick-fil-A

KFC's momentum is getting a major boost from the $5 "Fill Up" meal. Youtube/KFC KFC has executed a remarkable turnaround in its US business in the last year.

According to Citi Research analysts, the chain's momentum is getting a major boost from one popular promotion: The $5 "Fill Up" meal.

The meals include an entree, a drink, several sides, and a dessert — all for $5.

There are five different "Fill Up" combos featuring chicken tenders, chicken breasts, pot pie, and other options.

"We believe the positive sales momentum is likely to continue," Citi Research analysts wrote in a research note. "Of note, $5 Fill Ups continue to resonate very well and lower gas prices remain a tailwind."

Analysts said the recently launched $20 "Family Fill Up" should further drive sales.

KFC's same-store sales grew by by 7% and 3%, respectively, in the first two quarters of 2015. By comparison, comparable sales fell by more than 2% in the first half of last year.

Citi Research

The $5 meal could help KFC win back its position as the top chicken chain in the US by giving it a huge advantage over Chick-fil-A, where a similar meal would cost more than $7 in most markets.